The present invention relates to the sampling of oral fluids from an individual. More particularly the present invention relates to a saliva and oral fluid collection article to be used in the buccal cavity of a patient.
The sampling and testing of body fluids has long been used in the medical field to test and monitor the human body for various biochemical or physiological conditions or elements or just generally the state of health of a patient's body. Commonly, blood and urine samples are taken from patients for analysis to determine various levels of electrolytes, drops, hormones, metabolites, or other physiologically relevant biochemicals of the body. Recently, it has been found that a person's oral fluids or saliva may also be analyzed to provide valuable information regarding various biochemicals. It has been found that for a large number of molecules, direct correlation exists between the concentrations of particular substances in blood with that contained in oral fluids or saliva and also the concentrations of substances in urine correlate with those contained in saliva. Therefore, recently saliva has become a more desirable medium for monitoring of hormones, drugs, metabolites, or other physiologically relevant biochemicals in clinical chemistry and related fields.
The use of saliva as a testing medium is desirable since the saliva of a patient is readily available without the intrusive methods required in sampling of blood, by the use of syringes or other methods for instance, and without the undesirable nature of urine sampling which may cause other problems, such as monitoring of a patient while taking of a sample. Therefore use of saliva as a medium in biochemical and physiological analyses is desirable since it can be obtained by non-invasive methods.
While it has been found that saliva can be advantageously used in the analysis of the body's biochemistry there remain problems in the collection of saliva and in the handling of saliva by laboratory technicians. For instance, saliva contains mucopolysaccharides which contribute to the highly viscous, stringy or sticky consistency which creates problems in pipetting and measuring of the saliva. There are also sampling and handling problems due to the presence of particulate matter in the form of oral squames which preferably must be removed before analysis. Additionally, food or other particulate matter in the mouth presents further undesirable handling problems in that the particles must be removed from the sample before analysis. In addition, the intake of food substances can drastically affect the consistency and the appearance of saliva for extended periods of time further increasing the variable consistency and requiring difficult processing prior to analysis. Moreover, conditions of food substances can interfere with the analysis of saliva for both qualitative and quantitative measurements.
Variations in the consistency and contents of saliva also creates problems in its handling such that a centrifugal apparatus or other filtering or separation device must be used to separate and purify the sample from the undesirable particulate matter contained in the saliva prior to analysis. Additionally, the pipetting and measuring of saliva is difficult due to the stringy or viscous consistency. For these reasons, it is difficult for technicians to handle samples of saliva.
The sampling of saliva from patients may create further problems in that it is hard to obtain the sample inconspicuously from a patient. For instance, in curtain conditions if a patient knows that saliva is going to be collected this might have the adverse psychological effect of causing the patient's mouth to become dry thus creating problems in taking of a saliva sample. Additionally, some patients may even be hesitant to agree to sampling of saliva in their mouth or to expectorate for various reasons.
Saliva might contain large molecules or other components which might intefere with further analysis. For example, many hormones and drugs in saliva reflect the "free" component in blood, i.e. the fraction which is not bound to proteins. This fraction might constitute only a small percentage of the total amount ("bound" and "free") in blood. However, through small lacerations of the gum or the cheeks, blood, containing substances bound to protein(s), might enter the oral cavity and substantially increase the total concentration of substance to be analyzed. Thus, some "bound" substance might constitute a substantial amount of the total substance measured and be erroneous interpreted as "free". Thus, it is desirable to exclude larger molecules such as binding proteins. In another example, some enzyme proteins metabolize saliva components to metabolites. Thus, for accurate measurement of substances subject to enzymatic degradation, rapid and complete separation of enzymes from remaining fluid is required.